The present invention relates generally to agricultural machinery and, more particularly, to a method and an apparatus for ejecting a material from such machinery.
It is known from European Patent 0 631 717 A1 that a pivot unit with an impeller blower and a reciprocating fluid cylinder for pivoting the impeller blower can be provided for ejecting a material over a predetermined width.
It is also known that, directional control valves can be provided to drive the movement of a piston located in the fluid cylinder. The directional control valves act as a pressure medium by alternately opening and closing the fluid supply to connecting points arranged opposite to one another in an end region of the fluid cylinder. A storage device is provided to equalize pressure peaks at the turning points of the piston. The storage device is, however, subjected to high stress in case of high switching cycles.
It is therefore the object of the present invention to provide a method and an apparatus for ejecting a material, having a reliable and inexpensive means for driving a fluid cylinder.